For months now, columns and letters on this page have debated the wisdom of drilling for onshore oil in Santa Barbara County. Awareness of the issues within our county is acute.

Now, just across the county boundary in San Luis Obispo County, the proposal for a rail-spur extension at the Phillips 66 Santa Maria Refinery in the Nipomo Dunes is taking center stage.

At a recent public workshop in Arroyo Grande, residents raised many concerns about the project and its draft environmental impact report (DEIR), which discusses impacts on the refinery property, as well as impacts that might occur along the Union Pacific mainline, especially between the project and two rail hubs, one in Southern California and one in Northern California.

San Luis Obispo County has the authority to require mitigations to impacts on the property as part of its project approval authority, but is likely kept from imposing mitigations for the Union Pacific mainline impacts, because those fall under federal regulations.

As confirmed at that meeting, the county can deny the project based on significant impacts that cannot be mitigated, whether on site or on the mainline.

The DEIR says toxic air emissions at the refinery would be significant and unavoidable, because the cancer risk over a 30-year exposure period would be greater than the threshold established by the local air district. Even using the cleanest locomotives, which federal law may keep the county from requiring, the cancer risk would remain significant and unavoidable.

According to the Santa Maria Times, "The most significant impact identified in the revised DEIR would come from accidents on the main rail line that result in oil spills, fires and explosions near populated areas ..."

The DEIR found that primarily the Los Angeles area, Bay Area and Sacramento drive this risk, "since these are the locations where fairly long stretches of track are in close proximity to heavily populated areas."

If there is risk in Los Angeles, there is risk in Carpinteria, Santa Barbara, Goleta, Guadalupe and all points along the mainline in Santa Barbara County. There is, in fact, risk all along the mainline from wherever the crude oil originates.

The DEIR identifies other risks along the mainline. In the event of an oil spill, there could be significant and unavoidable impacts to agricultural crops and biological resources, "due to direct oiling, fire or surface and groundwater impacts." Cleanup activities could impact cultural resources.

Impacts on fire protection and emergency services along the mainline were found to be significant in the event of a fire or explosion. Remote volunteer fire departments are not equipped to deal with major oil spills. There could be significant and unavoidable toxic air emissions for areas along the mainline that are close to populated areas.

Greenhouse gas emissions in California could be significant and unavoidable, because they would exceed the air district’s threshold.

In all of these cases of potential mainline spills and emissions, the DEIR states that, "the county may be pre-empted by federal law from requiring mitigation for operations on the UPRR mainline tracks."

Comments on the DEIR are due on Nov. 24. Next year, the county Planning Commission will consider approval, and upon appeal so will the Board of Supervisors. Given the many significant and unavoidable environmental impacts that appear to be outside the county’s ability to mitigate, the county should deny the project.

People who are concerned about the impacts should comment on deficiencies in the DEIR and urge the San Luis Obispo County Planning Commission and Board of Supervisors to deny the project.

Ken Hough is executive director of Santa Barbara County Action Network (SB CAN). He can be reached at ken@sbcan.org. Looking Forward runs every Friday in the Santa Maria Times, providing a progressive viewpoint on local issues.